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How to make a Transparent Audio Reference XL Speaker Cable

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Picture of How to make a Transparent Audio Reference XL Speaker Cable
For my first project here on Instructables, I thought I'd start with what I think is about the coolest DIY project for high-end audio buffs.  This instructable will show you how to make a pair of $12,500 Transparent Audio Reference XL speaker cables for less than 200 bucks.  My project is based on a schematic I found on the internet, along with photos and x-rays of the insides of the Transparent Audio network box (see step 10 for everything I found).  Here are the parts you'll need:

½” black corrugated split tube, 20 ft. - $23.88
12/4 wound high strand count copper speaker wire, 20 ft – $11.20
½” black braided nylon tube, 20 ft. - $19.00
Plastic project boxes, 2 ea – $7.94
14 gauge copper wire, 10 ft - $7.59
Gold plated brass spades, 8 ea - $6.00 (I found them on eBay)
1” black heat-shrink tube, 2 ft. – $6.96
½” black heat-shrink tube, 4 ft – $11.12
½” red heat-shrink tube, 4 ft – $11.12
1000 picofarad capacitors, 2 ea - $2.12
31.7 ohm resistors, 2 ea - $1.15
½” oak dowel, 4” - $35.00 (for 36” dowel)
Black hot glue sticks, 3 ea – $3.94
Flux-core solder, 1 roll - $29.97

Total: $176.63

Here are the tools you'll need:

Pliers
Phillips screwdriver
Hot glue gun
Soldering iron
Heat gun (or hair dryer)
Wire cutters
Wire Strippers
Scissors
Masking Tape (I used a lot of it to help me stabilize things while I was working on them)
Razor knife or Xacto

 
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Step 1: Preparing the cable

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I'm just going to explain how to make one wire.  To make a pair, just double the instructions (obviously). :)

First, cut a ten foot length of your 12/4 wire and strip off the outer jacket.  You can discard the jacket as you won't need it at all.  Use masking tape to make sure that the twist of the cable stays the way it is.

Next, strip the ends of all the wires back about three quarters of an inch.  In my case, I had red, white, black, and green coated wires.  You will use two wires for each "leg" of the cable.  So, twist the ends of the red and white wires together.  Do the same thing for the black and green ones.  The red/white will be the positive leg and the black/green will be the negative.  Once you've got them twisted together, tin the ends so they'll stay that way while you're handling the cables.

Next, find the center of the wire (5 feet from either side) and cut the positive leg.  Strip back the insulation where you just cut, combine the wires and tin them the way you just did with the ends.  This center cut is where you will later add one of Transparent's "networks."

Step 2: Prepare the network box

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Set aside your cable for a minute and pick up your network boxes.  The plastic project boxes can be purchased at Radio Shack.  I chose the boxes that measure 5.75" by 2.75" by 2".  You could go smaller, but these will give you plenty of room to work inside them.

Mark the center point of the ends of the boxes.  Then, drill a hole in each end so your cable can go through the box.  The hole should be slightly smaller than 1/2 inch.  I drilled a pilot hole and then used a "stepping bit" to fine tune the hole.  Just take a short length of your corrugated tubing to test whether your hole is the right size.  The tubing should fit snugly.

Step 3: Build the main network

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Transparent's main "network" is simply an inductor measuring 2.5 micro Henries that is soldered into the path of the positive leg of the cable.

To make the inductor, take a two inch long piece of your oak dowel and wind your 14 gauge solid copper wire tightly around the dowel.  In order to get precisely 2.5 micro Henries, you will need something more complex than a multimeter.  I went to my buddy's shop and used his LCR meter to measure mine.

Side note: My opinion is that you don't have to make it too precise because a 2.5 micro Henry inductor really doesn't add very much inductance anyway.  When I measured the cable without the inductor soldered in, it measured 3 micro Henries by itself.  So, without the inductor, if I wanted to add 2.5 micro Henries of inductance, I just needed to lengthen the cable by about 8 feet.  Anyway, back to the instructions.

I found that if I wound tightly, I consistently got 2.35 to 2.55 micro Henries with 18 turns around the dowel.  I think that's a good rule of thumb to go by if you don't have a complex instrument to measure the inductor.

Once you're satisfied with your inductor, use masking tape to hold it in place around the dowel.  Tin the ends so they'll be easy to solder later.

Step 4: Solder in the network

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All you have to do here is solder in the inductor to the positive side of the cable and then fish the cable through the holes in your box.

It's easy to fish with no jacket on the wires and if you do it this way you don't run the risk of burning the box with your soldering iron.

Step 5: Dress up the cable

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Now that you have your main network complete, you can add some dressing to your cable to make it look nice and to protect it from wear and tear.

Take a five foot piece of your corrugated split tubing and wrap it around the cable on one side of the network box.  Then, take your nylon braid and slide it over the tubing.  Once it is at the end of the tubing next to your network box, gently work both layers through the hole in the box.  Once you've got them inside the box, use a zip tie and hot glue to keep them from sliding out again.  I like to use the black hot glue because of the lower melting point, which makes it more liquid that the standard stuff.  That way, you can work it around the cable to make sure it fills in any gaps between your braid and the hole in the box.

Repeat the process for the other side of the cable.

Step 6: The output network

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You may not have known this, but there is another, much smaller network on the output end of the Transparent Reference XL speaker cable.  It consists of a 1000 pF capacitor and a 31.7 ohm resistor.

All you do here is solder the cap and resistor together.  Then, use your soldering iron to melt away the insulation on the positive and negative legs of the cable 12 inches from the output end.  Using your soldering iron, solder together both wires of each leg and leave yourself a little "knob" to solder the network to.

The capacitor is soldered to the negative leg, and the resistor is soldered to the positive leg.

Once the solder has cooled slide a piece of the larger heat-shrink tubing over the network and apply some heat with a heat gun or hair dryer.  This will simply protect the network.

In order to do this step without damaging the tubing and nylon braid, I just moved them back a bit so they were out of the way.

At this point it's a good idea to take a pencil and draw an arrow on the main network box indicating the signal flow.  Like I said before, the small R/C network that we made should be attached to the output end, making the cable directional.

Step 7: Finishing the ends

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Take your spades and solder them to the ends of the cable.  I used a bench clamp to help me do it easily.

Now, take your smaller heat-shrink tube and slide them over your spades.  A red one should be used on the positive side and a black one on the negative side.  Make sure the heat-shrink overlaps onto the spade.  This will give some strain relief and it makes it look better.  Apply heat.

Notice that I didn't slide the heat-shrink on before I soldered on the spades.  I did it this way because heating the spades with your soldering iron takes a long time and causes the copper in the wire to heat up.  This can cause the tubing to shrink on you before you're ready for it.  So, get some spades that are small enough to slide your tubing over.

Next, take a piece of the larger black tubing (about 4 inches) and shrink it around where the tails come out of the corrugated/braided tubing.  Apply some heat to it, but be careful because if it gets too hot, the nylon braid will burn.

Repeat this process on both sides of the cable.

Step 8: Finish it up and burn it in

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Now all you have to do is attach the cap to the main network box.  I took a sharpie and wrote "in" and "out" on the bottom of the box so I wouldn't forget which way to hook up the cables.  I'll do something more permanent later.

I didn't do this yet, but you may want to fill your network box with hot glue.  I'm told that this will make it so the inductor won't vibrate as much (vibrations can cause noise).  It will also make the network boxes heavier, making them lay on the ground better.

To burn in the cables, just hook them up to your rig and let it play for a few days.  If you have a cable cooker, that might speed up the process.

Step 9: Conclusion

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I hope you found this project as fun to do as I did.  I've had them hooked up to my system for a couple of weeks now and they sound fantastic.

You may have asked yourself where I got the plans to build them.  Well, the internet is full of photos of Transparent cables that have been broken apart.  One of the sites that published these photos had a schematic of the design based on measurements the person took as he was taking apart the cable.  I'll attach the photos I found to the next step of this instructable.

Though it may not be an exact duplicate, I'd match my cables against genuine Transparent cables any day of the week.  Especially when you consider that they cost less than 2% of the original... and they sound fabulous!

Step 10: Photos/Schematic of Transparent Cables Found on the Internet


MikB4 years ago
A warning to "noobs in this field" (and others) -- the original item seems to be an Audiophile ( spelt A-u-d-i-o-p-h-o-o-l ) product. Nobody in their right mind spends $12,500 on some 10ft speaker cables, whatever "filter" or "network" is in the middle of it. And if you did, just think how much you'd have to spend on the amplifier, the speakers, the pristine sound sources ... to truly appreciate them.

And now that it's "for less than 200 bucks" -- it's still too expensive for what it is.

All you need is some reasonably thick good quality copper wire to connect your speaker and amplifier. Most "improvements" beyond that are just marketing and hype.

"Burning in" cables is another really strange pseudo-science part of the marketing. It means nothing ... other than a small extra charge on top of the already overpriced cables :)

Consider that if you were buying the parts to build these in bulk, it would cost even less than it cost you. So look at the mark-up on the originals! Ouch!

Under the "be nice" policy, it's impossible to say how bogus the original item really is. Nice work reverse engineering it and building it, that helps to expose what you're getting for your $12.5k, but I wouldn't go out of my way to build one of these!

I'd love to see some proper blind A/B tests of these cables against a 10 foot length of welding cable or ordinary 15 Amp mains cable.
translucentcable (author)  MikB4 years ago
Thanks for the compliment MikB. It was a fun project to reverse engineer.
Hi
I have a one question.
How many Volts must have this resistor and capacitor?
Thanks.
What If I needed a longer speaker cable, say 10 meters long? What would vary? Any Idea how transparent makes their XLR interconnects?
Bob Sm1 year ago

FYI, Transparent doesn't use your buddy's measurement equipment. They first use vastly more precise equipment that measures down to a 1/100th of a ohm, etc. and they use an entirely different cable than you can buy off the street. They also match the components to the cable and cable length, so just buying off the shelf cable and making an inductor that measures between 2.35 and 2.55 isn't going to be the same thing. I think your winding isn't tight enough, which might lead to the different measurements. Inductors usually have to be tightly wound and to not cause any ringing either.

I would first find out what test equipment these companies use, examine their actual cable since they have specific cable geometry, dielectrics, winding, and cable mfg which yield a specific end result and then they design the network around the cable and which frequency range they are trying to "neutralize", if you will. Good try though. Plus, how new is the cable in question that this was modeled after? Do they make the exact same design? They have introduced new product designs over the years.

Bob Sm1 year ago

Here's the flaws in your steps outlined.

1. You have to use Transparent's actual cable that they use in that specific Reference XL cable. Just buying raw cable does not mean it's the same as Transparent's raw cable. Same thing goes with MIT. You would have to use the exact same cable MIT uses in a specific product they make. 2. Transparent and MIT both have VERY expensive test equipment and they are performing VERY specific tests on the final outcome, and when they use capacitors, resistors, etc. they aren't using off the shelf components, they are using VERY tight tolerance components (MIT actually hand winds their own inductors), and they use VERY expensive measurement equipment, some of which costs about $100K to measure those values to ensure they are tightly matched. So, just buying off the shelf cable and components isn't going to produce the exact same result. Nice try, though.

Yes, MIT boxes are vastly different than Transparent. Yes, they both use capacitors, resistors, inductors in various "filter" designs, but they aren't the same as one another, and neither is the raw wire they use.

MIT also has a lot of patents, so no one can market anything that violates their patents.

Bottom line, don't say that this is a DIY Transparent or MIT cable project. It's just one's idea of how to do something similar, but yet it's NOT the same thing.

The only way to guarantee the same results is by taking your DIY cable and conducting the series of measurements that either Transparent or MIT conduct on their cables and then proving that they perform the same as yours. I doubt they will. So, just because you feel you can do the same thing for $200, you can't. Impossible. Nice try though.

cstevens122 years ago
I agree and yet disagree with the instructable and some posts. Let me explain:

First of all, I agree that it's ridiculous to spend 10K plus on speaker cables, even though I'm and audiophile (and yes, have actually been to the transparent factory)

The MIT boxes are vastly different than the Transparent boxes. Do not try to compare the two. The MIT boxes are a lot more complicated:

http://www.mitcables.com/pdf/TAS_190_Oracle_MA-X.pdf

Finally, the instructable fails to take a few things into account: First, even though the transparent cables are outrageously expensive, the "raw" cable used is of very high quality, and is a twisted pair design. If you use high quality twisted pair for your DIY cables, you will notice a significant improvement as compared to the instructable.

NOTE: most hi-fi stores that carry transparent will also the raw cable, I just picked up some 14-4 for $2.50 a foot.

Secondly, the inductor (and MIT boxes) change with different cable lengths, I'm unable (ignorance on my part) to provide technical detail as to how though. This may be room for experimentation.

Steven1112 years ago
Thanks for sharing. Always wondered what was in those network boxes.
I wonder, what the necessity is of having that inductor in the middle of the cable? A network box at the end of the cable seems to work fine for MIT cables. Surely that last 5 ft of cable has an insignificant effect. Might be interesting to try placing the whole network at the end of the cable in a separate box, with very short leads to the speaker terminals of course. It would make experimenting and swapping out different coils and caps easier.
kelyp2 years ago
Great you researched into this. Thanks so much. My experience in building LAN5, Goertz, cross coax and 6N twin leads, all varies slightly. I also have gold ribbon speakers, very wide bandwidth, no inductance, enabling 5.2 ohm load on the test lines. If you can get a signal generator and scope, view the reflected waves. I see this value coil will attenuate very effectively but will spread the signal down to below 1 MHz. It will round the reflected signal risetime slightly, but will sharpen the image remarkably, from my experience. Certainly, it will make the cable and load very stable. The capacitor will reduce the spike over 2 MHz, but not enough. Try a 0.1 uH for laughs and giggles. I like it. The resistor depends on your speaker, so I have no advice there, it is probably fine just as it is. The entire idea is fundamentally sound (pun intended!). And it is such a fun hobby. Thanks for sharing. Pete
HiFiMan4 years ago
It's basically just a copy cat version of the MIT cables.Before spending the money for parts on this do yourself a favor and go buy some Goertz speaker cables they sound far superior to this type of design.I know I own both types and I also build custom cables;loudspeakers;and electronics.Single conductors far outperform multi conductors in every respect.
For almost $200 for the parts I could build myself some self bi amped speakers with only 3 inch long speaker cables.
Now that's how you get transparent sound.
I agree with your statement about bi amped speakers...

About 20 years ago I was helplessly rtying to make a four way speaker to work properly... even using very tolerant 6 dB/Oct simple crossovers, and with a full electronics lab at hand, I found that the passive corssover was the worst offender in the whole chain of sound reproduction!

Later on, I tried the much straightforward process of multi-amplifying with Active crossovers. I still find amazing that most audiophiles spend huge amounts of money and effort pursuing perfection, buying or making a big, expensive and exquisite amplifier, and then throwing into the trash its signal when trying to connect thru a passive crossover with all its unavoidable flaws!

Even more amazing is the never ending quest for the "magical" cable, esoteric cones, ethereal sanbags and other "improvments" paid by wealthy people beieving in the black-magic approach to audio!

Kudos for saying that bi amplifiying (or multi-amplifying) is the best way to transparet sound! Amclaussen, Mexico City.
bhunter7364 years ago
I like the idea of making my own high end audio equipment. So let me first say thank you for this insightful project. :)

Next, since you have equipment to measure micro henries, I will have to assume you know a fair amount about electronic circuits and electrical flow.

Inserting a capacitor and resistor near the speaker will change the impedance for the amplifier, and ultimately change the relationship between the amplifier and the speaker just enough to have some slight coloration added to the audio, possibly so little most people would not hear it. I think this particular element may have more to do with the improved sound quality than anything else, assuming the wire is thick enough for the wattage it needs to carry. So the question is this; Do you think the effect of this cable could be further simplified to just the resistor and capacitor being attached at the speaker connect point making a <$5 audio upgrade?

Thanks.
The inductor is used to help attenuate RF signals and the capacitor and resistor(zobel network) help flatten out the the impedance rise at higher frequencies which the amp see's.The problem with zobel networks is there is no generic approach,each loudspeaker needs different values of components to operate correctly.
The best sound is achieved by having nothing but the voice coil on the output of the amp and using cables with a single strand of wire less than one foot in length.I generally reject any round wire more than 20awg for high frequencies due to skin effect problems that occur with larger conductors at high frequencies.
The longer the wire the bigger diameter it has to be.
The amp and speaker should be looked at as one unit.Anything and I mean anything added to the output of the amp colors the sound quality,especially resistors and inductors.
I have an instructable in the works to show everyone how to achieve ultra high resolution sound with minimal money.
Garu4 years ago
Hello.
First of all, great instructable, clean and well done.

And now, the questions! :)
I'm not American, so I have some problems in understanding what is a 12/4 wound high strand count copper speaker wire. What are the measures and characteristics of the cable (I live in Italy, so we have different measures)
Another thing: I looked on eBay for a 2.5 micro Henries inductor (I don't have the right equipment to test it and I'm also a bit lazy (: ), but I only found inductors with a much higher inductance. Is it better or I must use a 2.5 micro Henries inductance? I'm really a noob in this field so I kindly ask for an explanation.

Thanks and keep up with the good work!
translucentcable (author)  Garu4 years ago
Hello Garu,

If I were you, I'd just wind an inductor as I described in the project. 14 gauge solid copper wire wrapped tightly around a 1/2 inch dowel 18 times will be very close to 2.5 micro Henries. And as I said in the instructable, it really doesn't add that much inductance anyway.

12/4 wire is wire that comes with four conductors that are each 12 gauge. I'm not sure how that translates to your measurement system in Italy. High strand count refers to how many strands of copper there are in each of the four conductors. The wire I bought had 259 strands per conductor.
It's better to have LESS inductance in low impedance loads such as loudspeakers not add to the inductance that's already in the wire configuration already.Yes even a straight wire has inductance.
Better to move the amp close to the speaker use short connection,flat wire is best, and low capacitance cables(preferably balanced ones) going to the amps.
12 Guage in AWG (American spec) is the same as 4mm/sq in European spec, so just used 4mm/sq wire with a high strand count.
translucentcable (author)  fred_framus4 years ago
Excellent. Thanks Fred!
mike5004 years ago
I am shocked by the price difference of the original product and the remake. Did you also compare the cables listening to them? Is there also an instruction for the transparent interlink? Thanks for this instruction. It opened my eyes.
1scienceguy4 years ago
Very, very cool project. Thanks for taking the time to do it right!

Please continue to share your audio DIY projects. There are others of us out here that dabble in the same area.